package com.petot.claude.gwt.example.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.event.shared.EventBus;
import com.google.gwt.event.shared.SimpleEventBus;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DialogBox;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.web.bindery.requestfactory.shared.Receiver;
import com.petot.claude.gwt.example.client.request.ApplicationRequestFactory;
import com.petot.claude.gwt.example.shared.FieldVerifier;

/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class GwtExample implements EntryPoint {

    /**
     * The message displayed to the user when the server cannot be reached or
     * returns an error.
     */
    private static final String SERVER_ERROR = "An error occurred while "
        + "attempting to contact the server. Please check your network " + "connection and try again.";

    /**
     * Create a remote service proxy to talk to the server-side Greeting service.
     */
    private final GreetingServiceAsync greetingService = GWT.create( GreetingService.class );

    private final MyMessages messages = GWT.create( MyMessages.class );

    private final EventBus eventBus = new SimpleEventBus();
    private final ApplicationRequestFactory requestFactory = GWT.create( ApplicationRequestFactory.class );

    /**
     * This is the entry point method.
     */
    @Override
    public void onModuleLoad() {

        init();

        final Button sendButton = new Button( this.messages.sendButton() );
        final TextBox nameField = new TextBox();
        nameField.setText( this.messages.nameField() );
        final Label errorLabel = new Label();

        final Label personsNumberLb = new Label( "Loading..." );

        // We can add style names to widgets
        sendButton.addStyleName( "sendButton" );

        // Add the nameField and sendButton to the RootPanel
        // Use RootPanel.get() to get the entire body element
        RootPanel.get( "nameFieldContainer" ).add( nameField );
        RootPanel.get( "sendButtonContainer" ).add( sendButton );
        RootPanel.get( "errorLabelContainer" ).add( errorLabel );
        RootPanel.get( "personsNumberId" ).add( personsNumberLb );

        this.requestFactory.personRequest().count().fire( new Receiver<Long>() {

            @Override
            public void onSuccess( final Long personNumber ) {
                personsNumberLb.setText( personNumber.toString() );
            }

            @Override
            public void onFailure( final com.google.web.bindery.requestfactory.shared.ServerFailure error ) {
                super.onFailure( error );
            };

            @Override
            public void onConstraintViolation( final java.util.Set<javax.validation.ConstraintViolation<?>> violations ) {
                Window.alert( "violations" );
            };
        } );

        // Focus the cursor on the name field when the app loads
        nameField.setFocus( true );
        nameField.selectAll();

        // Create the popup dialog box
        final DialogBox dialogBox = new DialogBox();
        dialogBox.setText( "Remote Procedure Call" );
        dialogBox.setAnimationEnabled( true );
        final Button closeButton = new Button( "Close" );
        // We can set the id of a widget by accessing its Element
        closeButton.getElement().setId( "closeButton" );
        final Label textToServerLabel = new Label();
        final HTML serverResponseLabel = new HTML();
        VerticalPanel dialogVPanel = new VerticalPanel();
        dialogVPanel.addStyleName( "dialogVPanel" );
        dialogVPanel.add( new HTML( "<b>Sending name to the server:</b>" ) );
        dialogVPanel.add( textToServerLabel );
        dialogVPanel.add( new HTML( "<br><b>Server replies:</b>" ) );
        dialogVPanel.add( serverResponseLabel );
        dialogVPanel.setHorizontalAlignment( VerticalPanel.ALIGN_RIGHT );
        dialogVPanel.add( closeButton );
        dialogBox.setWidget( dialogVPanel );

        // Add a handler to close the DialogBox
        closeButton.addClickHandler( new ClickHandler() {

            @Override
            public void onClick( final ClickEvent event ) {
                dialogBox.hide();
                sendButton.setEnabled( true );
                sendButton.setFocus( true );
            }
        } );

        // Create a handler for the sendButton and nameField
        class MyHandler implements ClickHandler, KeyUpHandler {

            /**
             * Fired when the user clicks on the sendButton.
             */
            @Override
            public void onClick( final ClickEvent event ) {
                sendNameToServer();
            }

            /**
             * Fired when the user types in the nameField.
             */
            @Override
            public void onKeyUp( final KeyUpEvent event ) {
                if ( event.getNativeKeyCode() == KeyCodes.KEY_ENTER ) {
                    sendNameToServer();
                }
            }

            /**
             * Send the name from the nameField to the server and wait for a response.
             */
            private void sendNameToServer() {
                // First, we validate the input.
                errorLabel.setText( "" );
                String textToServer = nameField.getText();
                if ( !FieldVerifier.isValidName( textToServer ) ) {
                    errorLabel.setText( "Please enter at least four characters" );
                    return;
                }

                // Then, we send the input to the server.
                sendButton.setEnabled( false );
                textToServerLabel.setText( textToServer );
                serverResponseLabel.setText( "" );
                GwtExample.this.greetingService.greetServer( textToServer, new AsyncCallback<String>() {

                    @Override
                    public void onFailure( final Throwable caught ) {
                        // Show the RPC error message to the user
                        dialogBox.setText( "Remote Procedure Call - Failure" );
                        serverResponseLabel.addStyleName( "serverResponseLabelError" );
                        serverResponseLabel.setHTML( SERVER_ERROR );
                        dialogBox.center();
                        closeButton.setFocus( true );
                    }

                    @Override
                    public void onSuccess( final String result ) {
                        dialogBox.setText( "Remote Procedure Call" );
                        serverResponseLabel.removeStyleName( "serverResponseLabelError" );
                        serverResponseLabel.setHTML( result );
                        dialogBox.center();
                        closeButton.setFocus( true );
                    }
                } );
            }
        }

        // Add a handler to send the name to the server
        MyHandler handler = new MyHandler();
        sendButton.addClickHandler( handler );
        nameField.addKeyUpHandler( handler );
    }

    private void init() {

        this.requestFactory.initialize( this.eventBus );
    }
}
